New dates confirm beginnings of civilization in South America

Aerial overview of the central ceremonial zone at Porvenir in the Fortaleza Valley, taken from an adjacent hill. The open area between the mounds is about 550 yards across. Photo by Jonathan Haas, courtesy The Field Museum Full size image available here

CHICAGO-- Recent archaeological excavations and a new series of 95 radiocarbon dates confirm the presence of an extraordinary complex of more than 20 major ceremonial and urban centers extending back more than 5,000 years.

These sites in three valleys along the Peruvian coast represent the oldest civilization in the Andes. They are characterized by stone pyramids, large circular ceremonial structures and extensive areas of residential architecture.

This group of sites, including the previously reported sites of Aspero and Caral, include the largest settlements and the most massive structures in prehistoric Americas during the 3rd millennium BC. Taken together, they represent the earliest common roots of the Inca Empire.

Color mural depicts people making chicra net bags that were filled with rocks for pyramid construction. Mural by Jose Salazar Full size image available here

"The scale and sophistication of these sites is unheard of anywhere in the New World at this time, and almost any time," said Jonathan Haas, PhD, MacArthur Curator of Anthropology at The Field Museum and lead author of the research, which will be published in Nature Dec. 23, 2004. "The cultural pattern that emerged in this small area in the third millennium BC later established a foundation for 4,000 years of cultural florescence in other parts of the Andes."

This emerging civilization was based on agriculture and included social hierarchies, centralized decision-making and formalized religion. It thrived on a multifaceted economy based on inland irrigation of cotton and food plants, diverse marine resources and a well-developed system of regular exchange of goods.

Archaeologists map a cleared surface at the top of Mound C on Vinto Alto in the Pativilca Valley. Photo by Jonathan Haas, courtesy The Field Museum Full size image available here

The 95 new radiocarbon dates come from 13 of 20 similar sites in two of the Norte Chico's river valleys, Pativilca and Fortaleza. The new dates establish that the first inland sites with large-scale architecture were occupied by 3100 BC, more than 400 years earlier than any other similar sites in South America. Added to previously published dates from Caral and other sites in the neighboring Supe Valley, 127 radiocarbon dates are now available from the region, firmly establishing a precocious civilization thriving in the Norte Chico for more than 1,200 years.

"Equally as important as the dates themselves is the fact that dates between 2000 BC and 3000 BC come from almost every site where we tested and collected samples," said Winifred Creamer, Ph.D., a co-author of the research, professor at Northern Illinois University and Adjunct Curator at The Field Museum. "This wasn't a single site where people were doing something really unusual, but a whole region, a whole culture, where people were organized to produce something their world hadn't seen before. The people who built the first of these pyramids and plazas had no model to go by and no precedent to use in building monuments and organizing labor on a large scale."

The findings confirm the emergence, development and continuous occupation of a major cultural complex in this region during the Late Archaic period (3000 BC to 1800 BC). The period is also known as the Cotton Preceramic since the people in this region had not yet developed pottery but did grow cotton and weave cotton textiles. They also made the cotton into fishing nets and traded for fish from fishing communities along the coast.

In fact, earlier scholarship indicated that the emergence of complex society in this region at the beginning of the 3rd millennium BC was centered along the coast and based on maritime resources. Subsequent work demonstrated the existence of a substantial agriculturally based society at nearby inland sites. The new research indicates the inland sites were far more numerous, extensive and complexly organized than the coastal sites.

The inland sites range in area from 25 to more than 250 acres (10 to more than 100 hectares). They include from one to seven platform mounds – rectangular terraced pyramids up to 85 feet (26 meters) high. The largest of these pyramidal mounds range from 105,000 to more than 196,000 cubic yards (80,000 to more than 150,000 cubic meters) in volume.

"In Norte Chico, the path of cultural evolution in the Andean region diverged from a relatively simple hunting and gathering society to a much more complex pattern of social and political organization, with a mixed economy based on agriculture and marine exploitation," said Alvaro Ruiz, a graduate student in anthropology at Northern Illinois University and co-author of the research. "With this new information, we need to rethink our ideas about the economic, social and cultural development of the beginnings of civilization in Peru and South America."

Digital images available: